In-Store Pick A Brick
The Pick A Brick wall is where you can buy loose bricks by the cupful. These are usually the most popular, standard LEGO bricks, and are switched up regularly so it’s always worth checking what’s there every time you go – it will always be different.
Online Pick A Brick
According to LEGO’s website, Pick A Brick orders take 9-10 days to ship.
Online Bricks & Pieces
According to LEGO’s website, Bricks & Pieces orders take 7-10 days to ship.
BrickLink also created their own digital LEGO building software called Studio, where you can design your own Lego creations and upload the parts list to a BrickLink wanted list for easy purchasing.
With BrickLink you can not only buy individual LEGO bricks, but also buy LEGO sets (even discontinued ones), stickers, instruction manuals and boxes.